Fibre products such as for example egg boxes can be made from stock in a process where a fibre layer is created and shaped to a desired form whereafter the so shaped fibre product is dewatered and possibly subjected to some form of post-processing operation.
U.S. Pat. No. 6,103,179 discloses a method for producing a fibre product which is where a first male mould is immersed in a moulding tank containing stock. By means of vacuum, a fibre layer of predetermined thickness for the fibre product is formed. The first male mould is then removed from the moulding tank. A cyclical sequence of movements is performed with a female mould in which, in a first pressing stage, the female mould is brought under force against the male mould so that a first expressing of stock water occurs following which the fibre product is transferred to the female mould which is moved to a second position. The fibre product is then subjected to a second expressing whereafter the fibre product is subjected to final drying using microwave or IR radiation.
U.S. Pat. No. 5,603,808 discloses a mould for making pulp mouldings that includes a reticulate resin mould part of a three-dimensional shape. The resin mould part is metallized for reinforcement and mounted on a support member made of a resin, metal or aggregate. The support member has substantially the same three-dimensional shape as that of the reticulate resin mould and has openings to discharge water from openings of the metallized resin mould part. In one embodiment, the support member has a body of coarse particles bound together to form a porous structure. The particles of the porous structure are bound together by a binder or by sintering them.
It is desirable that forming tools for fibre objects be firm and strong such that they can withstand both underpressure and pressure that is caused by contact with counter-tools, for example during a pressing operation. It is also desirable that they have a sufficient permeability such that water may easily pass through the forming tools. In case fibres should accumulate inside a forming tool, it is also desirable that the tool can be cleaned from such fibres. It is also desirable that forming tools can be manufactured easily and at a low cost. With this in mind, the present invention has been developed in order to offer an improved forming tool for making fibre objects.